1. Field of the Invention
The present invention relates to a burner, and more particularly to a burner for a gas barbecue grill and that has a reliable low level heat function and a wide range heat output performance.
2. Description of Related Art
With reference to FIG. 6, a burner (40) for a gas barbecue grill in accordance with the prior art comprises a mixing tube (42) and a side tube (44). The burner (40) is secured in the housing of the gas barbecue grill and is connected to a gas source with a control valve (50), such that the burner (40) can heat or cook food with a flame from burning gas. The mixing tube (42) is connected with the control valve (50) at one end of the mixing tube (42). The side tube (44) is U-shaped and is connected to the other end of the mixing tube (42) at the middle portion of the side tube (44). The side tube (44) communicates with the mixing tube (42) and has multiple orifices (442) defined in the top of the side tube (44). Accordingly, the gas can be led into the side tube (44) through a hose, the control valve (50) and the mixing tube (42) and is emitted from the orifices (442) in the side tube (44). After igniting the gas, flames will occur on the side tube (44) to heat or to cook the food.
In addition, an adjusting knob (52) is mounted on the control valve (40) to adjust the passage in the control valve (50) for the gas passing therethrough so as to control the flames on the burner (40). The user can control the flames to cook the food or keep warm to the food by means of turning the adjusting knob (52). However, when user only wants to keep warm to the food and the user lowers the intensity of the flames, the quantity of gas emitted from the control valve (50) and into the mixing tube (42) is not enough to evenly spread in the mixing tube (42) and the side tube (44) with large diameters. Therefore, the flames on the conventional burner easily go out because that the gas cannot be continuously applied for burning. The gas keeps emitting from the orifices (442) in the side tube (44) when the flames go out, thereby causing an extremely dangerous condition. The conventional burner (40) has not a good performance in a low level heat function, and the use of the conventional burner (40) is not versatile.
To overcome the shortcomings, the present invention tends to provide a burner to mitigate or obviate the aforementioned problems.
The main objective of the invention is to provide a burner for a gas barbecue grill and having a reliable low level heat function and a wide range heat output performance. The burner has a mixing tube, a side tube, an auxiliary tube and a fire bridge. The side tube is secured to one end of the mixing tube and communicates with the mixing tube. Multiple orifices are defined in the top of the side tube. The auxiliary tube with a diameter smaller than that of the mixing tube is mounted above the mixing tube and is connected to the control valve which is connected to the mixing tube. Multiple orifices are defined in the top of the auxiliary tube. Consequently, the gas can be controlled to be led into the mixing tube or the auxiliary tube with the control valve. The fire bridge is connected between the mixing tube and the auxiliary tube. Multiple orifices are defined in the top of the fire bridge. With such a burner, the flames can be switched between the side tube and the auxiliary tube. With a diameter of the auxiliary tube being smaller than that of the mixing tube, the small quantity of gas can evenly spread in the auxiliary tube and the flame on the auxiliary tube will not go out even when the gas pressure is low. Therefore, the burner can provide a reliable low level heat function and a wide range heat output performance
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.